Continuous intensive quenching apparatus

ABSTRACT

An intensive quenching (IQ) apparatus and method of quenching heated parts is provided. The IQ apparatus includes a chute for placing parts into a tank including liquid quenchant. The parts fall through the quenchant in the chute and are received by a conveyor belt. The parts are then transported on the conveyor through an inner channel of a conduit. An agitation rate of the quenchant in the inner channel is increased by an agitator.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of and claims the benefit of U.S. Ser.No. 17/085,537 filed on Oct. 30, 2020 and entitled “CONTINUOUS INTENSIVEQUENCHING APPARATUS”, which is herein incorporated by reference in itsentirety. In addition, this application claims the benefit of U.S.62/934,229 filed on Nov. 12, 2019, which is herein incorporated byreference in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to metal fabrication and moreparticularly to heat treating metal.

BACKGROUND

Metal components are often heat treated. After leaving the heat-treatingfurnace, the metal components may be quenched in a tank. For example,hot parts may fall from a continuous heat-treating furnace belt througha quenching liquid (also referred to as a quenchant) in a tank and ontoa conveyor belt that transports the parts from the quench tank. Hotforgings and hot formed parts can be also quenched in a tank right afterforging or hot forming operations are completed. Common quenchants areoil or water.

SUMMARY

The present disclosure provides an apparatus for intensively quenchingparts using a conveyor that is partially located in a conduit and wherean agitation rate of quenchant in the conduit is increased by anagitator.

According to one aspect of the disclosure, there is provided anintensive quenching apparatus for cooling heated parts. The apparatusincludes a tank containing a quenchant, a chute, a conveyor, a conduit,and an agitator. The chute is configured to deliver the parts into thequenchant. The chute is at least partially filled with quenchant. Theconveyor is at least partially submerged in the quenchant and isconfigured to both receive the parts from an exit of the chute and totransport the received parts towards an exit from the quenchant. Theconduit has an internal passage. A portion of the conveyor is locatedwithin the internal passage. The agitator is configured to increase anagitation rate of the quenchant in the internal passage of the conduit.

Alternatively or additionally, the agitator is configured to cause anagitation rate in a portion of the internal passage that eliminates afilm boiling process from taking place on a surface of the parts.

Alternatively or additionally, the agitator is configured to cause theagitation rate to be greater than 4 ft/sec.

Alternatively or additionally, the apparatus also includes circuitryconfigured to adjust the agitation rate caused by the agitator based onrequired properties of the parts.

Alternatively or additionally, the chute includes openings configured toallow passage of quenchant between an exterior of the chute and aninterior of the chute.

Alternatively or additionally, the apparatus additionally includesnozzles configured to increase an agitation rate of the quenchant in thechute.

Alternatively or additionally, the apparatus further includes a pumpconfigured to provide supply quenchant from the tank to the nozzles forincreasing the agitation rate of the quenchant in the chute.

Alternatively or additionally, the inner passage includes bafflesconfigured to improve a uniformity of a flow distribution of thequenchant in the internal passage.

Alternatively or additionally, the exit from the quenchant is a surfaceof the quenchant.

Alternatively or additionally, the conveyor is configured to transportthe received parts out of the tank.

Alternatively or additionally, the portion of the conveyor locatedwithin the internal passage moves the parts upwardly towards the exitfrom the quenchant.

Alternatively or additionally, the conveyor includes a variable speedmotor configured to alter a speed of the conveyor, such that a dwelltime of the parts in the quenchant is varied depending on the speed ofthe conveyor.

Alternatively or additionally, the apparatus also including circuitryconfigured to receive properties of the parts and to adjust the speed ofthe conveyor based on the received properties of the parts.

Alternatively or additionally, the circuitry is configured to adjust thespeed of the conveyor such that a temperature of the parts leaving thequenchant is less than a temperature threshold.

Alternatively or additionally, the conveyor includes cleats havingopenings configured to allow quenchant flow through the cleats toimprove a uniformity of cooling of the parts.

According to another aspect of the disclosure, there is provided amethod for intensively quenching heated parts. The method includesdelivering the parts into a quenchant contained in a tank via a chute.The parts are received from the chute on a conveyor. A portion of theconveyor is located within an internal passage of a conduit. Anagitation rate of quenchant in the internal passage increases using anagitator. The received parts are transported towards an exit from thequenchant using the conveyor.

Alternatively or additionally, the increasing of the agitation rate ofthe quenchant in the internal passage includes increasing the agitationrate in a portion of the internal passage such that a film boilingprocess is eliminated from taking place on a surface of the parts.

Alternatively or additionally, the agitation rate of the quenchant inthe portion of the internal passage is increased to be greater than 4ft/sec.

Alternatively or additionally, the method also includes increasing anagitation rate of the quenchant in the chute using both nozzles tosupply quenchant to the chute and openings in the chute to allowquenchant to exit the chute.

Alternatively or additionally, the method further includes adjusting aspeed of the conveyor based on required properties of the parts.

Alternatively or additionally, the speed of the conveyor is adjustedsuch that a temperature of the parts leaving the quenchant is less thana temperature threshold.

While a number of features are described herein with respect toembodiments of the invention; features described with respect to a givenembodiment also may be employed in connection with other embodiments.The following description and the annexed drawings set forth certainillustrative embodiments of the invention. These embodiments areindicative, however, of but a few of the various ways in which theprinciples of the invention may be employed. Other objects, advantagesand novel features according to aspects of the invention will becomeapparent from the following detailed description when considered inconjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The annexed drawings, which are not necessarily to scale, show variousaspects of the invention in which similar reference numerals are used toindicate the same or similar parts in the various views.

FIG. 1 is a schematic diagram of an embodiment of an intensive quench(IQ) apparatus.

FIG. 2 is a schematic diagram of the IQ apparatus of FIG. 1 includingparts being quenched.

FIG. 3 is a schematic diagram of an alternative embodiment of the IQapparatus.

FIG. 4 is diagram of an exemplary embodiment of a cleat of a conveyor ofthe IQ apparatus.

FIG. 5 is a flow diagram of a method for intensively quenching parts.

The present invention is described below in detail with reference to thedrawings. In the drawings, each element with a reference number issimilar to other elements with the same reference number independent ofany letter designation following the reference number. In the text, areference number with a specific letter designation following thereference number refers to the specific element with the number andletter designation and a reference number without a specific letterdesignation refers to all elements with the same reference numberindependent of any letter designation following the reference number inthe drawings.

DETAILED DESCRIPTION

According to a general embodiment, an intensive quenching (IQ) apparatusis provided. The IQ apparatus includes a chute for placing parts into atank including liquid quenchant. The parts fall through the quenchant inthe chute and are received by a conveyor belt. The parts are thentransported on the conveyor through an inner channel of a conduit. Anagitation rate of the quenchant in the inner channel is increased by anagitator.

Turning to FIG. 1 an IQ apparatus 10 is shown including a tank 12containing a liquid quenchant 14, a chute 16, a conveyor 18, a conduit20 having an internal passage 22, and an agitator 24. Parts 26 pass intothe quenchant 14 via the chute 16 and are deposited onto the conveyor18. The conveyor 18 transports the parts 26 along the conveyor 18through the internal passage 22. Quenching of the parts 26 in theinternal passage 22 is improved by the agitator 24 increasing theagitation rate of the quenchant in the internal passage 22.

The tank 12 may be made of steel or any suitable material for containingthe quenchant 14. The quenchant in the tank 12 may have a temperaturewithin the range of the ambient temperature to approximately 120° F. Adepth of the quenchant 14 may be approximately 40 inches. In oneembodiment, the depth of the quenchant depends on the properties of thequenchant (e.g., thermal capacity) and the properties of the parts beingcooled (e.g., volume, temperature, etc.). The tank 12 may include atemperature controller (e.g., a cooler) configured to maintain atemperature of the quenchant 14 in the tank 12 below a predeterminedtemperature.

The quenchant 14 may be any suitable solution for cooling the parts 26.In one embodiment, the quenchant 14 may be a solution of mineral salts(e.g., sodium nitrite) in water or organic salts (e.g., DaphneIntensiQuench™) in water, both having a concentration of 5-20%. Inanother embodiment, the quenchant 14 may be an aqueous solution oforganic polymer (e.g., UCON™) having a typical concentration of 1-20%.

As shown in the embodiment depicted in FIG. 2 , the parts 26 areintroduced into the quenchant 14 via the chute 16 and the chute 16 is atleast partially filled with quenchant 14. Part 26 a is shown just afterentering the quenchant 14 and as the part 26 a is falling towards theconveyor 18. Part 26 b is further down the chute 16 and is approachingthe conveyor 18. Part 26 c has reached the conveyor 18 below an exit 27of the chute 16. Part 26 d has begun to move along the conveyor 18towards an exit 28 from the quenchant 14. Part 26 e is further along theconveyor 18 towards the exit 28. Part 26 f has exited the quenchant 14and is reaching the end of the conveyor 18. For example, the parts 26may be dropped from the conveyor 18 onto another actuator (e.g., anotherconveyor) for further transport of the parts 26 after exiting thequenchant 14.

While the IQ apparatus 10 is shown having a single chute 16, the IQapparatus 10 may have one or more chutes 16. The number of chutes, theconfiguration of the chutes, and dimensions of the chutes may depend onthe production setup. For example, if parts are corning from acontinuous furnace, the IQ apparatus 10 may include one chute having awidth slightly exceeding a width of the working space of the furnace(e.g., the chute width may be approximately 30 inches). In anotherexample, if the parts 26 are coming from hot forming presses, the numberof chutes may be equal to the number of hot forming presses. In thisexample, the exit 27 of each of the chutes may be near the same locationon the conveyor 18 so that the parts 26 have approximately the sametransit time along the conveyor 18 to the exit 28 from the quenchant 14.In another example, dimensions of the chute 16 may be determined bydimensions of the parts 26 (e.g., chute cross sectional dimensions maybe 6×6 inches for parts less than 6 inches along their largestdimension).

In the embodiment shown in FIG. 3 , the chute 16 includes openings 30for improving quenchant circulation within the chute 16. The openings 30are configured to allow passage of quenchant 14 between an exterior ofthe chute 16 and an interior of the chute 16. For example, openings 30may be located below a surface of the quenchant (also referred to as thequenchant level). The number of openings 30 and size of the openings 30may be dependent upon the properties of the chute 16, the quenchant 14,and/or the parts 16 being quenched.

In the embodiment depicted in FIG. 3 , the chute 16 additionallyincludes nozzles 32 for further improving quenchant agitation in thechute 16. The nozzles 32 are configured to avoid the initiation of anon-desired film boiling process on a surface of the part 26 when thepart 26 is falling through the chute. For example, the nozzles 32 may beused when quenching relatively thin parts (e.g., having a thickness ofapproximately ½ inch). The nozzles 32 may be positioned on one or moresides of the chute 16. In the depicted embodiment, the nozzles 32 arepositioned on opposite sides of the chute 16 (e.g., in a staggered oraligned arrangement).

A quenchant flow through the nozzles 32 may be provided by a pump 34that moves the quenchant from the tank 12 through the nozzles 32 intothe chute 16 and through the chute openings 30 back into the tank 12. Aswill be understood by one of ordinary skill in the art, a portion of thequenchant 14 flowing through the nozzles 32 may flow down the chute 16and merge with the quenchant flow provided by the agitator 24 in theinner channel 22. In one embodiment, the quenchant flow velocity fromthe nozzles 32 may be approximately 3-15 ft/sec. The quenchant flowvelocity from the nozzles 32 may depend upon properties of the chute 16and/or the parts 26.

The conveyor 18 is configured to transport the parts 26 towards an exit28 from the quenchant 14. For example, the conveyor 18 may transport theparts 26 to an actuator (such as a lift or another conveyor) thatremoves the parts 26 from the tank 12. Alternatively, as shown in FIGS.1-3 , the conveyor 18 may carry the parts 26 out of the tank 12. In oneembodiment, the conveyor 18 is inclined at an angle towards a surface ofthe quenchant 14. The conveyor 18 may be inclined at any suitable angle.For example, the angle may be approximately 25° (e.g., 15-35°).

In one embodiment, the conveyor 18 includes a variable speed motorconfigured to move the conveyor 18 at a speed that is dependent upon theproperties of the part 26 being transported. For example, a shape andthickness of the part 26 may affect the time required to properly quenchthe part. For this reason, the speed of the conveyor 18 may be adjustedusing the variable speed motor based upon such properties. As anexample, the IQ apparatus 10 may include circuitry 35 configured toadjust the agitation rate caused by the agitator based on properties ofthe parts 26. In one example, the circuitry 35 controls the speed of theconveyor 18 such that a temperature of parts 26 leaving the quenchant 14is less than a threshold temperature (e.g., 400° F.). In one example,the speed of the conveyor 18 is approximately 0.5-3 ft/sec. As will beunderstood by one of ordinary skill in the art, a length of the conveyor18 and the speed of the conveyor 18 both affect the dwell time of theparts 26 in the quenchant 14. For this reason, the speed of the conveyor18 may also be based on properties of the conveyor 18 (such as length).The speed of the conveyor 18 may be set such that the minimum dwell timeof each part 26 in the quenchant 14 is at least 3 seconds. In oneembodiment the speed of the conveyor 18 is set such that the dwell timeof each part 26 is between 7 and 20 seconds.

The circuitry 35 may have various implementations. For example, thecircuitry 35 may include any suitable device, such as a processor (e.g.,CPU), programmable circuit, integrated circuit, memory and I/O circuits,an application specific integrated circuit, microcontroller, complexprogrammable logic device, other programmable circuits, or the like. Thecircuitry 35 may also include a non-transitory computer readable medium,such as random access memory (RAM), a read-only memory (ROM), anerasable programmable read-only memory (EPROM or Flash memory), or anyother suitable medium. The circuitry 35 may be communicatively coupledto the computer readable medium and network interface through a systembus, mother board, or using any other suitable structure known in theart.

As shown in FIGS. 1-3 , a portion of the conveyor 18 is located withinthe internal passage 22 of the conduit 20. The internal passage 22 is atleast partially filed with the quenchant 14. The agitator 24 isconfigured to increase an agitation rate of the quenchant in theinternal passage 22. For example, the agitator 24 may be a rotatingpropeller positioned to direct a flow of the quenchant 14 into theinternal passage 22. By increasing an agitation rate of the quenchant inthe internal passage, the agitator 24 affects the quenching of parts 26being transported by the conveyor 18 in the internal passage 22. Forexample, the agitator 24 may rotate at a speed of 300 rpm, providing aquenchant agitation rate in at least a portion of the internal passage22 of approximately 2-8 ft/sec. The agitator 24 may provide an agitationrate that eliminates a film boiling process (which can unfavorablyaffect part distortion and microstructure) from taking place on asurface of the part at the beginning of the quench. For example, theagitator 24 may agitate the quenchant 14 at a rate of greater than 4ft/sec, greater than 6 ft/sec, between 2 and 8 ft/sec, or between 4 and8 ft/sec.

Turning to FIG. 3 , the conduit 20 may additionally include baffles 36for providing a more uniform flow distribution of quenchant in theinternal passage 20 (as compared to when baffles 36 are not present) toimprove uniform cooling of parts 26 being transported by the conveyor 18in the internal passage 20. For example, the conduit 20 may be a tubehaving an opening for receiving the conveyor 18 at a bottom portion andan exit from which the conveyor 18 exits the conduit 20 at an upperportion. The conduit 20 may also have another opening nearer theagitator 24 for allowing quenchant to enter the conduit 20. The baffles36 may be positioned in a portion of the internal passage 22 throughwhich the parts 26 are not transported (e.g., a portion to the right ofthe chute 16 as shown in FIG. 2 ).

Turning to FIG. 4 , the conveyor 18 may be formed from a belt consistingof a set of pans (also referred to as plates) 46 and traction structures48. The traction structures 48 may be protrusions extending from the pan46. Each pan 46 may engage with another pan 46 using engaging structures50 (e.g., hinges) located at edges of the pan 46. The conveyor 18 mayroll along a support structure using wheels 52. To elevate the part 26being transported from the conveyor belt for better uniformity ofcooling, the cleats 42 may be used. The cleats 42 may be attached to thepans 46. The cleats 42 may include openings to allow the quenchant 14 toflow (represented by the black arrow) freely along the conveyor belt toimprove a uniformity of cooling of the parts 26 supported by the cleats42.

A spacing (a distance) between cleats 42 may be determined based on asize of the parts 26 being transported, such that a slippage of theparts 26 down the conveyor 18 during transport is reduced.

The IQ system 10 may be used to cool parts of various temperatures,shapes, and sizes. For example, the parts 26 may have a temperature ofapproximately 1,500° F. (e.g., 1,200-1,800° F.). The parts 26 may have aminimum thickness of approximately ½ inch (e.g., 0.25-1 inch) and may beexiting any heating machine. For example, the heating machine may be acontinuous heat-treating furnace, forging press, or any other hotforming machine. The parts 26 similarly be made of any suitablematerial. For example, the parts 26 may be made of at least one of plaincarbon steels (e.g., 1040 steel), alloy steels (e.g., 5160 steel), orhigh-alloy steel (e.g., 4330 steel).

FIG. 5 depicts an embodiment of a method 100 for intensively quenchingheated parts. In process block 102, parts 26 are delivered into thequenchant 14 contained in the tank 12 via the chute 16. In process block104, the parts 26 from the chute 16 are received on the conveyor 18. Inprocess block 106, the agitation rate of the quenchant 14 in theinternal passage 22 is increased using the agitator 24. In process block108, the received parts 26 are transported towards an exit 28 from thequenchant 14 using the conveyor 18.

All ranges and ratio limits disclosed in the specification and claimsmay be combined in any manner. Unless specifically stated otherwise,references to “a,” “an,” and/or “the” may include one or more than one,and that reference to an item in the singular may also include the itemin the plural.

Although the invention has been shown and described with respect to acertain embodiment or embodiments, equivalent alterations andmodifications will occur to others skilled in the art upon the readingand understanding of this specification and the annexed drawings. Inparticular regard to the various functions performed by the abovedescribed elements (components, assemblies, devices, compositions,etc.), the terms (including a reference to a “means”) used to describesuch elements are intended to correspond, unless otherwise indicated, toany element which performs the specified function of the describedelement (i.e., that is functionally equivalent), even though notstructurally equivalent to the disclosed structure which performs thefunction in the herein illustrated exemplary embodiment or embodimentsof the invention. In addition, while a particular feature of theinvention may have been described above with respect to only one or moreof several illustrated embodiments, such feature may be combined withone or more other features of the other embodiments, as may be desiredand advantageous for any given or particular application.

What is claimed is:
 1. A method for intensively quenching heated parts,the method including: delivering the parts into a quenchant contained ina tank via a chute; receiving the parts from the chute on a conveyor,wherein a portion of the conveyor is located within an internal passageof a conduit; increasing an agitation rate of quenchant in the internalpassage using an agitator; and transporting the received parts towardsan exit from the quenchant using the conveyor.
 2. The method of claim 1,wherein the increasing of the agitation rate of the quenchant in theinternal passage includes increasing the agitation rate in a portion ofthe internal passage such that a film boiling process is eliminated fromtaking place on a surface of the parts.
 3. The method of claim 2,wherein the agitation rate of the quenchant in the portion of theinternal passage is increased to be greater than 4 ft/sec.
 4. The methodof claim 1, further comprising increasing an agitation rate of thequenchant in the chute using both nozzles to supply quenchant to thechute and openings in the chute to allow quenchant to exit the chute. 5.The method of claim 1, further comprising adjusting a speed of theconveyor based on properties of the parts.
 6. The method of claim 5,wherein the speed of the conveyor is adjusted such that a temperature ofthe parts leaving the quenchant is less than a temperature threshold.